You will want to supervise for the first few times to see how it goes, there could be trouble or it could go easy. The more room and places to hide and escape will make things easier. Be ready to separate if things get rough, than try again the next day until everyone mostly ignores each other and there isn't excessive pecking. Having things the young chicks can slip under or through that the bigger ones can't, can give the younger ones a place to be safe.